Small-Scale Modeling Techniques for Reinforced Concrete Structures Subjected to Seismic Loads

摘要

The report focuses on improved physical modeling techniques for small-scale reinforced concrete structures subjected to seismic loadings. Particular emphasis is placed on the development of a model concrete mix to accurately model the important strength and stiffness properties of full-scale prototype concrete. The gradation of aggregate used in the mix, along with the aggregate to cement ratio, are shown to be critical in achieving sufficiently low tensile strength while still maintaining acceptable critical strain levels at compressive failure of the model concrete. Four types of model reinforcement with different bond characteristics are also studied. Using these model materials, the adequacy of bond between model concrete and model reinforcement is then examined with experiments on a series of 1/6 scale model assemblages of a prototype beam subjected to reversing loads. It is concluded that small scale elements fabricated with annealed, threaded rod reinforcement best meet the similitude requirements for strength, stiffness, cyclic degradation of stiffness, energy absorption during fully reversing loads, and failure mode after severe cycling.